1. Field of the Invention
The present invention relates to a parallel computer in which calculation nodes (data processing nodes) are connected through a network, and more specifically to a parallel computer including a file system for storing and processing a massive volume of data.
2. Description of the Related Art
In recent years, the need for computer systems enabling high-speed processing of high-volume data is increasing, especially in the field of science technology calculation. In a parallel computer, the data processing time has been shortened by parallelized programs according to a developed parallel processing technique.
However, when high-volume data for programs performed in the parallel computer are input to and output from a storage device, the input and output of the data cause a bottleneck for the whole process in the parallel computer. Therefore, a high-speed technique for the data input/output processing becomes important in order to get the best performance from the programs.
In a conventional parallel computer system, a single disk storage device or a plurality of disk storage devices are connected to a node or a computer for inputting and outputting data (herein after referred to as an I/O node), which is used as a file server.
The I/O node receives a file input/output request from another node so as to input data to or output data from a disk storage device, and sends the process result to the node which issued the request. However, because the communication capacity, the power of the CPU, and the ability to input and output data of one I/O node have their limits, the performance of the I/O node decreases when a file input/output request for a high volume of data is issued by a node or a large number of file input/output requests are simultaneously sent from a plurality of nodes.
Accordingly, the conventional parallel computer system has a problem in that system performance is reduced by the bottleneck of data input/output in the I/O node, especially when a plurality of application programs which require mass data processing are performed simultaneously in the parallel computer system.